<!DOCTYPE html>
<style>
#a {
    background-image: url(../resources/bluesquare.png);
    background-repeat: repeat;
    height: 1em;
}
#b {
    float: left;
    background-color: white;
}
</style>
<div id="a"><span id="b">This test passes if there is blue to the right</span></div>